This invention relates to optical fibre cables and in particular optical fibre packages for use in submarine cables and methods of manufacturing them.
In a cable core of one submarine cable design the optical fibres are housed within a pressure tube formed, for example, from a copper C-section The optical fibres are embedded together with a strength member wire in extruded plastics material and together form an optical fibre package. The residual volume between the pressure tube and the optical fibre package is filled with a water blocking compound such as HYVIS 2000 (HYVIS is a registered Trade Mark). One process for producing such a cable core involves a number of discrete process steps, namely: procuring a HYTREL 40D, (HYTREL is a Registered Trade Mark) coated copper clad steel King wire (strength member wire); concurrent melting of the HYTREL coating, positioning optical fibres around the King wire, and over-extrusion with HYTREL; insertion of the thus produced package together with HYVIS 2000 into a C-section, followed by C-section closure; cladding with copper tape and providing a longitudinal sealing weld.
An object of the present invention is to provide an alternative method of producing a submarine cable core.